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Subwoofer setup

Turn up the gain on the subs, keep the crossover the same, measure again, then perhaps try crossing at 80Hz, you have to just experiment with the phase, ideally a flat ( less wiggly as possible) FR which has around a 10dB drop from 20-20kHz.
There is a limit to what you can achieve in a shared domestic room which is largely ‘untreated’ as good as you can and then enjoy.
Keith


Thanks will do when I increase the gain it boosts the 50hz range. Will play around. Cheers.
 
Thanks,

I adjusted the toe in and same problem. I'm actually wondering if the issue could be the analogue input in the Naim Atom. I found an article on it and when measured it had an early roll off due to digitising everything

https://www.audiosciencereview.com/...ds/naim-uniti-atom-review-streamer-amp.35213/

Not sure if this could account for the measurements I'm getting or if that isn't possible.

I added in an old measurement I had from a different speaker and it looks the same. Something seems to be dragging the treble down.

The highest line on the chart is the different speaker

Treble-roll-off.jpg


The other option is that something is wrong with the speakers?

Cheers

Sam
All very interesting. Looking at the blue trace, if you’ve measured both channels together I wouldn’t worry about the elevated treble. That region won’t be accurate when both channels are measured together but lower frequencies should be OK. In any case adjust the toe in for what “sounds” best for you.

Looking at the red and green traces it doesn’t look too bad at all. I’ve had a look at your subs manual and it would appear that the gain/level and crossover aren’t labelled as such so it is suck it and see. If it was me I would keep the crossover at the same value and increase the level on the sub. if, having done that, you get a dip before 50Hz than increase the crossover than try with a slightly higher crossover, if there is bump try reducing it a bit.

In the grand scheme of things they are quite small subs so that means you won’t get much clean output below about 30-35Hz although the fact that you have two will certainly help. Because they are small it might be worth moving the subs to the front corners of the room so that the room will reinforce them. If you do this don’t forget to try flipping the phase switch as the time relationship with the mains will have changed. The REL manual has useful information on finding the best position.

You mentioned earlier placing the subs on granite blocks. Opinions vary on this! I have found that it depends on the quality of the sub (better subs will have heavier cabinets that don’t play along with drivers) and the type of flooring. Suspended wood flooring can be a problem and I have had a measurable improvement with the sub on a heavy paving slab with sorbothane isolation to the floor. The idea is that the sound should be coming from the driver not the floor playing along. It has to be said that the floor playing along might be better for some people. I don’t think we can be too dogmatic about this. In the end what sounds best to you is best.

Hope this helps but if you’d rather keep to input from one person than just say and I’ll refrain (well, try to refrain!!!) from commenting further.
 
All very interesting. Looking at the blue trace, if you’ve measured both channels together I wouldn’t worry about the elevated treble. That region won’t be accurate when both channels are measured together but lower frequencies should be OK. In any case adjust the toe in for what “sounds” best for you.

Looking at the red and green traces it doesn’t look too bad at all. I’ve had a look at your subs manual and it would appear that the gain/level and crossover aren’t labelled as such so it is suck it and see. If it was me I would keep the crossover at the same value and increase the level on the sub. if, having done that, you get a dip before 50Hz than increase the crossover than try with a slightly higher crossover, if there is bump try reducing it a bit.

In the grand scheme of things they are quite small subs so that means you won’t get much clean output below about 30-35Hz although the fact that you have two will certainly help. Because they are small it might be worth moving the subs to the front corners of the room so that the room will reinforce them. If you do this don’t forget to try flipping the phase switch as the time relationship with the mains will have changed. The REL manual has useful information on finding the best position.

You mentioned earlier placing the subs on granite blocks. Opinions vary on this! I have found that it depends on the quality of the sub (better subs will have heavier cabinets that don’t play along with drivers) and the type of flooring. Suspended wood flooring can be a problem and I have had a measurable improvement with the sub on a heavy paving slab with sorbothane isolation to the floor. The idea is that the sound should be coming from the driver not the floor playing along. It has to be said that the floor playing along might be better for some people. I don’t think we can be too dogmatic about this. In the end what sounds best to you is best.

Hope this helps but if you’d rather keep to input from one person than just say and I’ll refrain (well, try to refrain!!!) from commenting further.


Thanks,

Any Input is very welcome. I think I am fighting against the room most. I can only move one sub to the corner due to room constraints. At present they are just in side the speakers.

I have played around largely by flicking switches. The issue seems to be that no matter what I do I end up boosting things in 50 60hz range and still get the strange treble roll off.

This is the best I can manage is these two which I appreciate is pretty poor but I will have another play around but maybe the room will be the deciding factor.

Speakers-and-sub.jpg
 
Sam it’s fine we can lop off the 50/70Hz peaks with Roon, but what’s happened to the treble , you haven’t changed the angle of the speakers?
Goes without saying but it is important not to change the mic position once you have established mlp.
Keith
 
Sam it’s fine we can lop off the 50/70Hz peaks with Roon, but what’s happened to the treble , you haven’t changed the angle of the speakers?
Goes without saying but it is important not to change the mic position once you have established mlp.
Keith
The sudden nosedive in the treble looks like both speakers are being measured at the same time.
 
Hmm, I’m assuming your latest plots are both channels measured together? If so that might account for the treble variance in that small changes in the mic position can alter the measured response. I think I would try reducing the crossover on the subs a bit and remeasuring. Ideally you want to get the response as good as possible before tidying up with EQ in Roon. Most importantly how, is it sounding now? Is the bass booming?
 
Sam it’s fine we can lop off the 50/70Hz peaks with Roon, but what’s happened to the treble , you haven’t changed the angle of the speakers?
Goes without saying but it is important not to change the mic position once you have established mlp.
Keith

Thats a good question.

Since yesterday I had a play around with toe in and checked leads and so forth trying to find a reason for the treble drop off. I also noticed I had put an input trim on previously which I removed incase it was causing the abrupt treble roll off.

I was getting the issue with the bass disappearing even on the speakers alone so I uninstalled rew and reinstalled which seemed to resolve it.

The mic is in the listening position still. I wonder if I have set REW up incorrectly. The following steps were followed

Install Rew
Connect from headphone jack to RCA aux.

Connect UMIK 1 to usb and select non 90 degree file.

Set SPL to about 75db using main volume. I do feel I have to get the volume pretty loud to get to 75db. Perhaps this could be the issue.
The other possibility is the cable from the laptop it was a reasonable price one from Amazon.

I guess I will have to check things again. The treble looks lower overall but doesn't have the aggressive roll off.

Cheers
 
The sudden nosedive in the treble looks like both speakers are being measured at the same time.

They are being measured together. There is the potential when my son came home he couldn't resist the allure of moving the mic a bit. I'm pointed at the centre image not directly at the speakers. If the mic got moved it wasn't noticeable.
 
Hmm, I’m assuming your latest plots are both channels measured together? If so that might account for the treble variance in that small changes in the mic position can alter the measured response. I think I would try reducing the crossover on the subs a bit and remeasuring. Ideally you want to get the response as good as possible before tidying up with EQ in Roon. Most importantly how, is it sounding now? Is the bass booming?

Pretty loud but not quite booming. I put a soundtrack on and it has a cinema feel. I tried the Raven by Rebecca Pigeon and it was okish but one note had a reasonable amount of resonance.
 
They are being measured together. There is the potential when my son came home he couldn't resist the allure of moving the mic a bit. I'm pointed at the centre image not directly at the speakers. If the mic got moved it wasn't noticeable.
Measuring left & right speakers together is fine for bass but can give hugely inaccurate treble measurements because the much shorter wavelengths arriving at the mic from uneven distances can cancel each other out. That's why you often see huge changes in treble response even if the mic is only moved a few mm's. The treble measurements will be far more consistent if you measure each speaker individually.
 
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Yes two optical inputs.
Hi Keith,

Still not tried with windows device. What I did was use REWs ability to create sweeps from a usb device thus eliminating the cable. Im not what your view on these measurements is?

L and R measured together uppermost line in graph. L and R measured separately below with no sub

usb-no-sub.jpg


L and R measured together uppermost line in graph. L and R measured separately below with sub.

usb-with-sub.jpg
 
A horizontal target which you have in the first set can sound a bit thin in domestic terms, so I ‘prefer’ the second with a bit more bass, response tails off pretty quickly below 50Hz though?
How do they sound which do you prefer with or without sub?
If there is any overhang around 50-80Hz we can reduce that with Roon.
Best,
Keith
 
A horizontal target which you have in the first set can sound a bit thin in domestic terms, so I ‘prefer’ the second with a bit more bass, response tails off pretty quickly below 50Hz though?
How do they sound which do you prefer with or without sub?
If there is any overhang around 50-80Hz we can reduce that with Roon.
Best,
Keith

Im not quite sure of the terminology but when you say below 50hz can it go higher? I was aiming for 75db no particular reason.

I like it with the subs and maybe because it a small room the bass is pretty good to my mind. If increase the gain I can get the 20 - 50 up but the spike around the 50 -70 just gets bigger. I know it can be reduced but I use a Rega P6 so it would be good to use that still sometimes. I realise the correction on roon will only apply to that.
 


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