How on earth is my logitech sub as loud as my monolith?

willhub

willhub

willhub

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This is something I'm curious of.

Now to get this out of the way, loudness and quality are two different things I know, and my Z5500's 10" sub doesn't sound as good in fact sounds horrendous compared to my Monolith probably due to the crossover because of the tiny sattelites, but what has me stumped is it's ability to go LOUD!

Now below 30Hz the Monolith Plus does take the lead, easilly, but above that? I don't think the Monolith can compete it seems, both tried in the same spot, and the Z5500 was absoloutly shaking the rafters more than my BK Monolith plus with its 95 Litre cabinet and its 12" 500W RMS subwoofer.

As I say, both in the same place, not to say the Monolith wasn't shaking the rafters it was, but the smaller 10" subwoofer seems to be putting out higher volumes and the driver moves less also, in a smaller cabinet.

Am I missing something? Shouldn't the Monolith Plus be crunching the Z5500 up? It kind of annoys me and makes me think perhaps my Monolith Plus is underperforming but I've had it up where it's nearly pushing its 22mm XLIM
 
The Logitech is ported higher therefore it can play louder. But not as low. And at low frequencies it'll bottom out. IE compare svs 16-41 pc plus against svs 25-39 pc plus. The 25hz svs is ported higher. It has several dB advantage across the frequency range.

Same for silver grey foxes pa subwoofers, they play very loud 125db but reach down to 47 Hz.
 
hornetstinger said:
The Logitech is ported higher therefore it can play louder. But not as low. And at low frequencies it'll bottom out. IE compare svs 16-41 pc plus against svs 25-39 pc plus. The 25hz svs is ported higher. It has several dB advantage across the frequency range.

Same for silver grey foxes pa subwoofers, they play very loud 125db but reach down to 47 Hz.
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so if the Z5500 has the ability to go down to 20Hz it would probability be insufficiently loud? I assume the Monolith should eat it in that case?
 
Correct, the Logitech portrd much higher say 40hz, under that dB output will drop, the cone will reach its limit and thd go through the roof.

That loudness effect probably 50 or so, very chest pumpy but not low.

When I had my pc ultra I ported it to 11hz. No way would the Logitech reach that low with that output it'll just blow up.

Since the Logitech is ported it'll probably be 20db down at 20hz.

Now if it was sealed it'll be flatter as sealed box drop off differently compared to ported.

Compare a couple of svs sealed and ported design frequency response of the same amp/driver ie SB 4000 and pb 4000

Bk don't release frequency response graphs so have to look elseware.

Look at response of that lousy pa sub I forget the model, it has a hump at 80hz I think then drops off massively.
 
if I blocked the port in the Monolith would it effect the upper frequencies ? it seems to stiffen the driver a bit
 
Don't do that it's not designed to be sealed you will damage it. My pc ultra 13 also offered sealed mode after you plugged all three ports you flick the switch to sealed. Yours does not have that.

Only do this onported subs which are designed to, hsu, svs, and there's Swedish brand forget the name.
 
hornetstinger said:
Don't do that it's not designed to be sealed you will damage it. My pc ultra 13 also offered sealed mode after you plugged all three ports you flick the switch to sealed. Yours does not have that.



Only do this onported subs which are designed to, hsu, svs, and there's Swedish brand forget the name.
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How would it damage it?

what does the switch do?

I'm sure Tom from BK said it was ok to bung the port and it wouldn't damage it
 
Email one of the companies that make pluggable subs and ask them what the switch does, it's been a few yesrs. But from memory it applies different eq and different dB/octave slope.

It will lower dB output as well, ported design make it more efficient. That's why high output sealed subs need lots of power. My pc ultra 13 definitely can go louder than my SB ultra 13. It's the same driver, and the old pc had bash 750w the SB ultra has 1000w sledge.
 
they would be awesome but I don't have money for a new sub.

the Monolith Plus has the Eminence Lab 12C drivers with an Xmax of around 12mm I think? Xlim is around 22mm? I've seen people talking about this and seem to suggest that going up to the xlim is actually ok for this sub?
 
From what I remember, the z5500 is quite peaky at fs, around 33hz. It should have 5-6db of headroom over the monolith in that range, but the monolith should have 5-6db over the z5500 above that and a crap tone of headroom below it because it has a flatter responce. It's been a while size I've looked at the figures but I'm sure if you search for max SPL charts on both you'll probably see that. In English, this all translate to the z5500 being capable of going VERY loud between 30 and 35hz and rolling off pretty sharply either side.

Try a frequency sweep from 80 to 20hz on both and you'll hear that peak on the z5500 straight away I bet.
 
Saying that, is the XMAX of 13mm +/- or just + because it doesn't specify. 6.5mm one way seems awfully low to the point I'd always be bottoming it out but it hasn't made any noises any scratches or smells, nothing, all fine.

Definitely at one point had it over 13mm one way and it wasn't complaining.

**edit - +/- Xmax is 26mm and XLIM is 44.

Surely pushing 40 +/- or 20mm one way is safe then?


james.miller said:
From what I remember, the z5500 is quite peaky at fs, around 33hz. It should have 5-6db of headroom over the monolith in that range, but the monolith should have 5-6db over the z5500 above that and a crap tone of headroom below it because it has a flatter responce. It's been a while size I've looked at the figures but I'm sure if you search for max SPL charts on both you'll probably see that. In English, this all translate to the z5500 being capable of going VERY loud between 30 and 35hz and rolling off pretty sharply either side.

Try a frequency sweep from 80 to 20hz on both and you'll hear that peak on the z5500 straight away I bet.
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I will give it a try once GF not in as was giving her anxiety.
 
Not sure of exact specifics but cone surround on mine has a lot of possible back and forth movement, like the sunfire true subwoofer surround, the bk subs visually look they have less.
 
The BK is just like a run of the mill surround you normally would expect.

The driver is an Eminence Lab 12C 6Ohm version I believe (400W RMS).

This is "supposed" to be a good driver, the likes of Odeon use it in their cinemas, or did, weather or not that gives it a good reputation or has any meaning or not is probably personal opinion.
 
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