Should the MJ Pro 50 (mk1) be used with the high level input for music?

[admin_exported]

I just got a used one and the bass sounds really muddy and distorts with not much input and there's not attack or definition. I've read here that for a stereo music system the high level input should be used. MJ said there's no difference but something doesn't sound right with the sub if the reviews are anything to go by! I've tried mono and stereo rca cables from the preamp out and record out of my amp.

Cheers.

 

[Anonymous]

Anyone?

 

[The_Lhc]

I wouldn't use the record out as it's probably a fixed-level output meaning the volume of the sub won't go up and down with the volume of the amp. High level would be better for music if you can try it but your description of the sound gives the impression there's something wrong with the sub and I doubt switching to the high level input would make any difference to that.

 

[Inter_Voice]

Mine is MJ Pro MKII look like this http://www.mjacoustics.co.uk/MJ_Acoustics/Product_html/PRO_50_MKII.htm

I am using the high level input and the bass is very tight and solid for stereo 2 channel hifi listening.

Just try the two inputs yourself and see if there is a difference. May be the problem is with the MKI version but I don't have an answer

 

[Anonymous]

I wouldn't use the record out as it's probably a fixed-level output meaning the volume of the sub won't go up and down with the volume of the amp. High level would be better for music if you can try it but your description of the sound gives the impression there's something wrong with the sub and I doubt switching to the high level input would make any difference to that.

No that was a mistake, i was advised to use that but i switched back to the preamp out and set the crossover a bit higher and lowered the volume and i'm starting to find the right balance. I'm using a cheap rca cable and apparently i need to spend £20-30 on a decent subwoofer cable so i'll get the speakon then i can set it up for music and movies.

 

[Anonymous]

Mine is MJ Pro MKII look like this http://www.mjacoustics.co.uk/MJ_Acoustics/Product_html/PRO_50_MKII.htm

I am using the high level input and the bass is very tight and solid for stereo 2 channel hifi listening.

Just try the two inputs yourself and see if there is a difference. May be the problem is with the MKI version but I don't have an answer

Thanks. Have you tried the low level? I think now the Pro50 is doing what it should be but it just needs setting up properly, it's not a big sub so doesn't have a lot of power but it does go pretty deep.

I'll order a speakon cable next week anyway so i can use both inputs but i want to get the best possible sound out of the sub and the high level is for stereo amp which is what i'm using so hopefully that is the issue but if anyone with the Pro50 can say for sure that would be great.

Cheers!

 

[Anonymous]

Can anyone with a mk1 tell me if it should be capable of decent levels. Mine is not and that's the problem. It can't keep up with the Dalis and it sounds good when everything is playing but on it's own it just don't sound right and the driver seems to distort with low frequency stuff like dubstep at what i would consider low levels, i'm not driving it hard at all. :?

I know it's an old sub but i thought it would have a bit more clout.

 

[drummerman]

Can anyone with a mk1 tell me if it should be capable of decent levels. Mine is not and that's the problem. It can't keep up with the Dalis and it sounds good when everything is playing but on it's own it just don't sound right and the driver seems to distort with low frequency stuff like dubstep at what i would consider low levels, i'm not driving it hard at all. :?

I know it's an old sub but i thought it would have a bit more clout.

I have your sub in Ruark Vita 50 form (same as far as I know other than looks) and use the speakon connection. Used it with numerous different system and never encountered problems. Clean and fast though its probably not the sub I'd choose to shake foundations but then, I'm not into that.

regards

 

[Anonymous]

Thanks. Would you mind listening to a sample if i upload one? Mine just sounds very dull on it's own but with the Dalis it sounds like the bass is projecting from the speakers and it sounds good so i'm well confused. I expected clean accurate sub bass and that's not what i'm hearing from the sub itself but you might be able to tell whether it's knackered or i need to get the speakon cable. 🙂

Btw i don't want floor shaking bass, just clean accurate low end. The distortion i think is just the driver struggling with the lower frequencies as it improved when i cut the bass with some eq.

 

[drummerman]

Thanks. Would you mind listening to a sample if i upload one? Mine just sounds very dull on it's own but with the Dalis it sounds like the bass is projecting from the speakers and it sounds good so i'm well confused. I expected clean accurate sub bass and that's not what i'm hearing but you might be able to tell whether i've got a dodgy sub or need to get the speakon cable. 🙂

Not sure I understand what you mean but a sub is not meant to be listened to on its own. It should just very subtly underpin what is already there and not be audible as a separate entity, for music anyway. Its probably more a question of what you're missing (if anything) when it (sub) is not in the system than an immediate 'wow' when it is. These are also low powered with a small cone and enclosure, 'sub bass' is not on the menu but the Pro 50 is fast with little overhang. Like I said, I've used it with different systems, actives including and never found it wanting.

I have a feeling you may need something bigger and beefier.

I may be wrong but I think frOg used to have one of these too. Perhaps he will churn in.

regards

 

[Anonymous]

Not sure I understand what you mean but a sub is not meant to be listened to on its own. It should just very subtly underpin what is already there and not be audible as a separate entity, for music anyway. Its probably more a question of what you're missing (if anything) when it (sub) is not in the system than an immediate 'wow' when it is. These are also low powered with a small cone and enclosure, 'sub bass' is not on the menu but the Pro 50 is fast with little overhang. Like I said, I've used it with different systems, actives including and never found it wanting.

I have a feeling you may need something bigger and beefier.

I may be wrong but I think frOg used to have one of these too. Perhaps he will churn in.

regards

I bought the sub not really knowing what role it would fulfill or how well it would integrate but the seller told me it was loud at low level so i was expecting something a bit more impressive so i started listening to the sub in isolation and found that with slight volume or crossover increases the lowest frequencies would distort. It does sound good but i think i'm expecting a bit too much out of it. I'll get the high level cable anyway then i can set to level for audio as i'm constantly adjusting it and see how it sounds for music. 🙂

So do you run it a low low volume? I have it about halfway with the crossover someway between 40 and 90hz depending on what i'm listening to. I'm not expecting chest thumping bass just a nice linear low end response. I went for a small sub cause of neighbours but i probably should have gone for a bigger enclosure. Next time! >)

 

[Anonymous]

It's just amazing how quiet the sub is on it's own in relation to my bookshelfs. The Dalis can go quite loud without any distortion or room issues, i guess i've just got to find the balance. Of course if i keep the volume low on the sub i'll have more headroom. It's my first hifi sub so i'm putting it down to rookie mistakes. 😛

 

[drummerman]

Teejuk, I dont know what the frequency roll-off of your speakers is but lets assume it is around 60 - 80hz, fairly normal for standard sized stand mounted ones. - Therefore try and set your sub at around the same frequency.

Subwoofer volume ... try and start with very little while your hifi is playing. Turn the sub off and listen out for something missing ... usually some scale and solidity to the sound. If not, turn up a little more, repeat the switching off and so on until you find that your system sounds better with than without it. You should not be able to pinpoint the subwoofer as a source.

If you can't find a satisfactory setting or miss 'slam' then you may simply want another product.

As for subwoofer cables, as mentioned by yourself earlier in the thread, there is no great magic involved in either speakon connection or the cable itself. - I can't remember how much I paid for mine but it wasn't 30 quid. Try ebay.

regards

 

[fr0g]

Hallo!

What dm says.

Basically you cannot expect the Pro 50 mk1 to shake the walls. At reasonable levels it goes very low (30Hz), but you can't expect an 8" cone to make your chest squirm.

Don't ever try to guage its level by listening to it alone...Low bass is not as "loud" to the human ear as frequencies in the mid-range.

All the sub should be doing (with music) is giving extra body to the sound.

Also. Put the sub where you sit. Then put the music on...Now walk around the room and see where the bass is deepest...that's where you should put it if possible.

Also, depending on the amp you may need to alter the phase. Usually either 0 or 180 is best, but I have found 90 to be perfect too...depends on amplifier.

Level...For me, never more than 50-60%.

I used both high and low level and found it similar. Best IMO is to use an AV amp with sub connector, set speakers to small and let the AV amp split the signal. This makes the overall sound cleaner.

By the way, I still use mine in my AV system, and it does a pretty good job considering the room size. But again, you aint gonna get REFERENCE levels.

 

[Anonymous]

Teejuk, I dont know what the frequency roll-off of your speakers is but lets assume it is around 60 - 80hz, fairly normal for standard sized stand mounted ones. - Therefore try and set your sub at around the same frequency.

Subwoofer volume ... try and start with very little while your hifi is playing. Turn the sub off and listen out for something missing ... usually some scale and solidity to the sound. If not, turn up a little more, repeat the switching off and so on until you find that your system sounds better with than without it. You should not be able to pinpoint the subwoofer as a source.

If you can't find a satisfactory setting or miss 'slam' then you may simply want another product.

As for subwoofer cables, as mentioned by yourself earlier in the thread, there is no great magic involved in either speakon connection or the cable itself. - I can't remember how much I paid for mine but it wasn't 30 quid. Try ebay.

regards

It's about 60hz but i don't know exactly where that is on the Pro 50 (question for fr0g 😉) so i'm using my ears. It seems to have been as simple as having the level too high on the sub, i backed it off a few db and now i have more headroom.

Mid volume for AV use is good but lower for audio so i'll have to get the high level cable then i can try it out anyway which i guess is the good thing with having two inputs. I didn't want slam, just an accurate response and good extension but i just wanted to determine that there wasn't a fault or the sub was anemic before getting into all the setup and measuring stuff plus i'll be getting spikes/feet and probably some sort of isolation platform.

Anyway, thanks a lot for your help drummerman! :cheers:

 

[Anonymous]

Hallo!

What dm says.

Basically you cannot expect the Pro 50 mk1 to shake the walls. At reasonable levels it goes very low (30Hz), but you can't expect an 8" cone to make your chest squirm.

Don't ever try to guage its level by listening to it alone...Low bass is not as "loud" to the human ear as frequencies in the mid-range.

All the sub should be doing (with music) is giving extra body to the sound.

Also. Put the sub where you sit. Then put the music on...Now walk around the room and see where the bass is deepest...that's where you should put it if possible.

Also, depending on the amp you may need to alter the phase. Usually either 0 or 180 is best, but I have found 90 to be perfect too...depends on amplifier.

Level...For me, never more than 50-60%.

I used both high and low level and found it similar. Best IMO is to use an AV amp with sub connector, set speakers to small and let the AV amp split the signal. This makes the overall sound cleaner.

By the way, I still use mine in my AV system, and it does a pretty good job considering the room size. But again, you aint gonna get REFERENCE levels.

Yes i think i'm finding the sweetspot now. I don't know where the frequencies are on the sub as there are no incremental markings so i've used my ears, think it's around 60hz where the Dalis roll off, how do you work out the frequecy points on the sub? Volume very low, about 30-40% on the sub and now i have extra headroom to turn it up without overloading the woofer. I was playing some dubstep yesterday with Arc 2 and the full range bass correction enabled and i was getting some pretty deep bass at decent levels so it's got some depth if i need it. It's funny you mention 30hz cause i found putting a eq cut around there prevents the the distortion. Also phase at 90 seems to be spot on. The bass aint trouserflapping but it's pretty good considering the size of my room.

@drummerman, i've seen the speakon cable for around £18.99 which aint too bad but what i'm hearing now is much more in line with what i was hoping to attain by adding a sub! The level is a factor though, although i couldn't hear the sub at mid volume it was too loud to allow for much input before overloading and this was while setting up so i thought there was something wrong.

I hope this will help anyone setting up a sub, keep the subs level low if your running into issues, i think midway is a bit too high but perhaps it's different for larger subs? And back off the volume relative to your main output. Regarding cables, what's the minimum amount i should spend? I bought a 10m Fisual cable just for setting up but what i'm hearing sounds pretty good, could it be improved with a y cable?

Anyway thanks again guys for responding. I think i'm cooking with bass now. 😀

 

[Anonymous]

That was until today when the sub started humming!

fr0g, if you see this can you tell me if your MJ Pro 50 starts to distort with volume midway when you turn up the main volume? Thanks.

 

[fr0g]

That was until today when the sub started humming!

fr0g, if you see this can you tell me if your MJ Pro 50 starts to distort with volume midway when you turn up the main volume? Thanks.

1. The cable you have is fine. I have one of the same brand.

As for your question, I'm not entirely sure what you mean. I have mine set up in an AV system now(have a BK XXLS400 for my main music 😀 ) and I never get distortion at the levels I use. The sub is connected low level to the Yamaha RX V667 sub out and is at 50% volume.

I think your problem is possibly one of expectation and volume. I use a couple of test tracks from Aphex twin and Biosphere for bass testing. Ageispolis / Oi-1 are great bass testers. You absoutely will not get volume and clarity with a Pro 50 mk1 with these tracks. In the end it's an 8" sub with a 50 watt amp. So bass-heads after volume need not apply.

Save up and replace it with a BK if that's what you need.

If not it's a fantastic sub. Extremely quick and musical and easy to integrate.

 

[Anonymous]

I mean at moderate levels. don't get me wrong, it's not big bass i want but accurate low end for a 2.1 mixing setup. I can only hear it when i isolate the sub, that's the problem but the level i'm at seems to low for that to be occuring. :?

Yeah it's not a studio sub but i like i say i wanted a sealed one and the blue sky subs cost a bit more. I thought i might get another so i have one for each speaker eventually but i can't go too big cause of neighbours though what i've heard in the past few days i've liked. I took a risk buying such an old sub second hand but thankfully help is at hand, i should be able to get it sorted.

Oh yeah the seller told me it was loud with the volume at 1/10, that's where the expectation came from. If he'd have said it's good at low level but don't push it i wouldn't have thought there was an issue with it.

Cheers.

 

[fr0g]

I mean at moderate levels. don't get me wrong, it's not big bass i want but accurate low end for a 2.1 mixing setup. I can only hear it when i isolate the sub, that's the problem but the level i'm at seems to low for that to be occuring. :?

Yeah it's not a studio sub but i like i say i wanted a sealed one and the blue sky subs cost a bit more. I thought i might get another so i have one for each speaker eventually but i can't go too big cause of neighbours though what i've heard in the past few days i've liked. I took a risk buying such an old sub second hand but thankfully help is at hand, i should be able to get it sorted.

Oh yeah the seller told me it was loud with the volume at 1/10, that's where the expectation came from. If he'd have said it's good at low level but don't push it i wouldn't have thought there was an issue with it.

Cheers.

Yep, loud at 1 is a pushing the truth rather a bit. 🙂

But basically you shouldn't really be able to "hear" it anyway. It simply compliments the speakers filling in where they tail off. It IS an excellent sub used correctly as you seem to have found. Good luck...

 

[drummerman]

... or just solidify soft bass as happened when I used it with some K2's and a pair of MA floorstanders.

regards

 

[Anonymous]

Yep, loud at 1 is a pushing the truth rather a bit. 🙂

But basically you shouldn't really be able to "hear" it anyway. It simply compliments the speakers filling in where they tail off. It IS an excellent sub used correctly as you seem to have found. Good luck...

That's what it's doing with the level midway, 1 would not be worth having the sub on! When i isolated it and heard the distortion and muddy low end i thought it was broken (when i think about i've never really listened to a sub in isolation). Cutting the bass below 30hz definitely helped as does backing of the level and crossover for higher spls. I still don't know exactly where 60hz is, MJ said 90 was midway but shouldn't it be 100hz? Increments would really help!

It is a nice little sub, feel i paid a bit over the odds for it given the age and conditon though, i've already got to send the amp to get serviced.

 

[Anonymous]

... or just solidify soft bass as happened when I used it with some K2's and a pair of MA floorstanders.

regards

I read the blurb about it hanging with speakers costing £10k so i was expecting something pretty amazing! If it's the same sub as the Ruark and Minotaur isn't it just overpriced or are they actually different?

That's what it does though, adds the low end body to kick and upper mid bass and percussion, sounds great on orchestral and live stuff as well as electronic.

 

[Anonymous]

I thought, if the sub level has to be low why not connect both inputs? So i tried connecting both preamp outs to the amp, better low end definition and cleaner sub bass even at low levels. Kicks seem punchier and i can feel more of the sub bass so i think i'm reaching a plateau with it now. :cheer:

Of course it could just be due to moving the sub a few inches as i didn't have a long enough rca cable. :rofl:

 

[davo]

I have happily owned one for many years. Most that can be said has been said already. I would add that it is room (as well as location within the room)dependent. It worked better in my old listening room than in my new listening room. In my old room I could indeed get good results with only about 10% gain (8 o'clock position). That's with Castle speakers rolling off at about 48Hz and the cut-off of the sub set at minimum - 40Hz. I confirmed with the manufacturer that the "cut off" is in fact a gentle taper and using a set-up disc and a RadioShack/Tandy analyser was able to see the sub augmenting from about 35Hz to 55Hz.

The audible effect is however fairly subtle as others have said. I notice it most with organ music - after all not much else goes below 50Hz.