Hi all,
I'm starting to think about expanding my current stereo subwoofer set up from one SB Acoustics 8" SB23MFCL45-4 in a 12L sealed cabinet per side to two sealed subs per side.
I bought the initial drivers 16 months ago and here's my query:
If I bought another two would they match the pair I have now? I have no idea on the long term consistency of TS parameters that come out of the factory.
My instincts lead me to think that there will not be that much difference and if I go ahead with this idea I should keep each pair together from their respective purchase date. However the asymmetry in my mind may drive me nuts.
What are peoples thoughts here?
Cheers!
I'm starting to think about expanding my current stereo subwoofer set up from one SB Acoustics 8" SB23MFCL45-4 in a 12L sealed cabinet per side to two sealed subs per side.
I bought the initial drivers 16 months ago and here's my query:
If I bought another two would they match the pair I have now? I have no idea on the long term consistency of TS parameters that come out of the factory.
My instincts lead me to think that there will not be that much difference and if I go ahead with this idea I should keep each pair together from their respective purchase date. However the asymmetry in my mind may drive me nuts.
What are peoples thoughts here?
Cheers!
Greets!
If published specs are the same, then with no online contact source available can either assume they're 'close enough' or contact your previous provider and ask them to confirm, etc..
Ideally measure them all to match, otherwise your way.
GM
If published specs are the same, then with no online contact source available can either assume they're 'close enough' or contact your previous provider and ask them to confirm, etc..
Ideally measure them all to match, otherwise your way.
GM
Small sealed subs are quite insensitive to T/S parameters as the air spring will dominate the spider compliance. As long as there have not been design changes to the motor there should no difference in performance.
+1 on what the others said.
Two other points.
1)
Your basic idea is good. More subs (sources) are good. If you haven't already looked, check out the Geddes and Harmon ideas / documents on placing swarms of subs.
2)
For subs, room effects are often lots more important than a little bit of variation in Qts or whatever.
If you were going to measure (and correct for) one or the other, I'd suggest getting a USB mic and measuring the in-room response, rather than getting a woofer tester and measuring the TS parameters.
Two other points.
1)
Your basic idea is good. More subs (sources) are good. If you haven't already looked, check out the Geddes and Harmon ideas / documents on placing swarms of subs.
2)
For subs, room effects are often lots more important than a little bit of variation in Qts or whatever.
If you were going to measure (and correct for) one or the other, I'd suggest getting a USB mic and measuring the in-room response, rather than getting a woofer tester and measuring the TS parameters.
If you can get a Umik-1 or another calibrated mic or/ and a minidsp it will help u a lot, the room have much to say how subwoofers performs and set up more together 🙂
Cheers for the input, people.
Point taken on all counts. However, the questions was not so much about measuring it but them being conistent without measuring/before buying 🙂
I just ordered an IMG Stageline STA-400D with hypex UCD modules for bass and I will get more bounce to the ounce if I have four 8ohm in two paralleled pairs. Shame the amp won't run at 2ohms as I wouldn't have to replace the lot for max amp power. Hmmmm.
Point taken on all counts. However, the questions was not so much about measuring it but them being conistent without measuring/before buying 🙂
I just ordered an IMG Stageline STA-400D with hypex UCD modules for bass and I will get more bounce to the ounce if I have four 8ohm in two paralleled pairs. Shame the amp won't run at 2ohms as I wouldn't have to replace the lot for max amp power. Hmmmm.
"However, the questions was not so much about measuring it but them being conistent without measuring/before buying"
Whether or not you measure, a bit of variation in TS specs will cause maybe a 1dB variation is response, for a sealed sub. IMO, not worth worrying over.
Whether or not you measure, a bit of variation in sub location will cause maybe a 20dB variation is response. IMO, that is much more worthy of your attention.
Example:
The Pros and Cons of Multiple Subwoofers - HomeTheaterReview
Whether of not you measure, going to 4 subs, as you plan to do, is probably a very good thing to do - particularly if you follow some of the positioning tips. The link I give states:
"As you can see, the response in seating position one is flatter with two subs and even flatter with four."
The improvement from increasing the number of sources is much, much bigger than any improvement you'd get from modest tweaks to the tuning of a single sub.
Whether or not you measure, a bit of variation in TS specs will cause maybe a 1dB variation is response, for a sealed sub. IMO, not worth worrying over.
Whether or not you measure, a bit of variation in sub location will cause maybe a 20dB variation is response. IMO, that is much more worthy of your attention.
Example:
The Pros and Cons of Multiple Subwoofers - HomeTheaterReview
Whether of not you measure, going to 4 subs, as you plan to do, is probably a very good thing to do - particularly if you follow some of the positioning tips. The link I give states:
"As you can see, the response in seating position one is flatter with two subs and even flatter with four."
The improvement from increasing the number of sources is much, much bigger than any improvement you'd get from modest tweaks to the tuning of a single sub.
Yeah, not sure the other half would go for a scattered array of subs but I know where you are coming from, cheers.
I am planning to have the two subs share a 30L+ cabinet on each side.
Here is the current stack. The sub cabinet is left over from a previous modular system made of MDF. The sub cab will match the 18mm birch ply of the midbass and be mad braced.
For posterity here is an impedance sweep of one of the SB23MFCL45-4 drivers in the 15L cabinet. With a QTS of 0.69 I might try and aim a little lower in the new cabinets.
I have ordered the two extra subs today and will swap them in to these old cabinets to let them get acclimatized to their surroundings and do a apples-for-apples comparison.
I am planning to have the two subs share a 30L+ cabinet on each side.
Here is the current stack. The sub cabinet is left over from a previous modular system made of MDF. The sub cab will match the 18mm birch ply of the midbass and be mad braced.
For posterity here is an impedance sweep of one of the SB23MFCL45-4 drivers in the 15L cabinet. With a QTS of 0.69 I might try and aim a little lower in the new cabinets.
I have ordered the two extra subs today and will swap them in to these old cabinets to let them get acclimatized to their surroundings and do a apples-for-apples comparison.
Attachments
New drivers have arrived!
Unfortunately I didn't save the DATS projet from the last measurement but from the comparison image below they differ very little.
For example:
Old Fs = 31.3hz / 30.7hz
New Fs = 30.3hz / 29.6hz
That's close enough for me!
Thanks all for the input.
Unfortunately I didn't save the DATS projet from the last measurement but from the comparison image below they differ very little.
For example:
Old Fs = 31.3hz / 30.7hz
New Fs = 30.3hz / 29.6hz
That's close enough for me!
Thanks all for the input.
