What is the best way of reducing the Bass - load on a pair of Spender BC1's to protect them from excessive transients when driven at high - ish levels?
Option 1 - A separate Bass Speaker Enclosure with crossover feeding the BC1's, without modification to their crossovers.
Option 2 - A separate Bass Speaker Enclosure, driven by a 405, with filtering at source to split drive between Main Amplifier and 405?
Option 1 - A separate Bass Speaker Enclosure with crossover feeding the BC1's, without modification to their crossovers.
Option 2 - A separate Bass Speaker Enclosure, driven by a 405, with filtering at source to split drive between Main Amplifier and 405?
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I'm not 100% sure what you mean, but I think it's the following: your option 1 will add a separate bass module, which will use an additional passive crossover to divide the signal between the BC1s and the bass module. The BC1s and bass modules would together be driven by your existing power amp. Yes?
I'd say this is possible but not often done. If you want to explore it further, a good guide would the the late Jeff Bagby's paper here: https://meniscus.lightningbasehoste...he-Kairos-and-Continuum-Three-Way-Writeup.pdf
Your option 2, is, I think, to have a line-level crossover of some sort, and separate power amps for the bass module and the BC1s. Yes? This would be the more common route. It could be done with a commercial subwoofer, as these usually contain a high-pass filter for the main speakers. Or it could be done with an analogue active crossover unit (fairly rare nowadays) or a DSP unit such as a miniDSP Flex.
I'd say this is possible but not often done. If you want to explore it further, a good guide would the the late Jeff Bagby's paper here: https://meniscus.lightningbasehoste...he-Kairos-and-Continuum-Three-Way-Writeup.pdf
Your option 2, is, I think, to have a line-level crossover of some sort, and separate power amps for the bass module and the BC1s. Yes? This would be the more common route. It could be done with a commercial subwoofer, as these usually contain a high-pass filter for the main speakers. Or it could be done with an analogue active crossover unit (fairly rare nowadays) or a DSP unit such as a miniDSP Flex.
Yes ianbo, my first option is exactly that and thanks for Jeff Bagby's paper. Although it is an option, I think it is beyond me, given the limited test facilities and as I said earlier; elsewhere, it probably wouldn't result in anything that does justice to my Spendors.
Option two is the direction I was thinking is more achievable. My 909 would be primarily for the Spendors and my 405 - which I am reluctant to part with: as is my 303, the supplementary Bass unit.
As all three amplifiers are rated at 775mV? input and my Streamer, 2V, I currently use a passive preamp, which has 6db. insertion loss naturally. Very little reworking would be required to insert filtering between, to separate the two bands for the amplifiers.
It then becomes, I hope, a lot easier to design and enclosure for the supplementary bass unit. As for the best crossover frequency remains to be seen as does the choice of bass driver.
Option two is the direction I was thinking is more achievable. My 909 would be primarily for the Spendors and my 405 - which I am reluctant to part with: as is my 303, the supplementary Bass unit.
As all three amplifiers are rated at 775mV? input and my Streamer, 2V, I currently use a passive preamp, which has 6db. insertion loss naturally. Very little reworking would be required to insert filtering between, to separate the two bands for the amplifiers.
It then becomes, I hope, a lot easier to design and enclosure for the supplementary bass unit. As for the best crossover frequency remains to be seen as does the choice of bass driver.
Fair enough. Either way, the challenge will be to get everything to integrate. If you are putting the woofer units under the BC1s, you can cross higher than if they're further away. You could go as high as 150-200 Hz, if you want.
But the woofer boxes would have to be pretty compact to fit under the Spendors. Something like the SB Satori WO24P-8 in 30 litres sealed might work?
(Incidentally I'm not 100% sure what you mean about the insertion loss on the passive pre. What type of passive pre are you using?)
But the woofer boxes would have to be pretty compact to fit under the Spendors. Something like the SB Satori WO24P-8 in 30 litres sealed might work?
(Incidentally I'm not 100% sure what you mean about the insertion loss on the passive pre. What type of passive pre are you using?)
Insertion loss - just the through loss when the pre - amp is in circuit. Actually, it is a rather nice, Variable Loudness Control {switched in ten steps}. I modified it to remove the high lift and gives a really nice linear increase in lift below about 800Hz., but flat as a pancake above.However, it adds 6db. attenuation to the path. The component tolerances are really tight and I can't believe I got it for a song. Mounted in a quality case, it doesn't look out of place with my 909 or Sugden. Plus, there is sufficient room left over for a couple of crossover networks.
My hearing is not particularly good and it is quite pronounced in the bass region, at low levels, which makes the 909 sound over - bright. It does wonders in bringing out the lower notes when listening at low levels.
Yes, where to mount/fit them. I was thinking of fabricating the enclosure to sit the Spendors on and doing away with the trolleys. Also, perhaps three switchable cross - over frequencies, at least whilst "playing around" with the design - if that's what one would call it. 150 - 200 Hz. would certainly shift a fair bit away from the Spender Bass/Midrange unit and afford more protection.
I also have a very nice volume control - case mounted - which could be used to adjust the level between the Spenders and the LF units.
However, this is just precursory thinking, given we have yet to move into our new home yet.
My hearing is not particularly good and it is quite pronounced in the bass region, at low levels, which makes the 909 sound over - bright. It does wonders in bringing out the lower notes when listening at low levels.
Yes, where to mount/fit them. I was thinking of fabricating the enclosure to sit the Spendors on and doing away with the trolleys. Also, perhaps three switchable cross - over frequencies, at least whilst "playing around" with the design - if that's what one would call it. 150 - 200 Hz. would certainly shift a fair bit away from the Spender Bass/Midrange unit and afford more protection.
I also have a very nice volume control - case mounted - which could be used to adjust the level between the Spenders and the LF units.
However, this is just precursory thinking, given we have yet to move into our new home yet.
OK, I see now - the pre is not just a passive attenuator, clearly! You're obviously thinking line-level active filters. That sounds fine. - if I were doing something like this the Pass DIY Biamp 6-24 would appeal.
Actually no, purely passive. I wanted to remain gain free in respect of everything other than the amps. The only active crossovers I was really aware of are Stax, which are/were silly money.
However, your suggestion actually chimes with me, insofar as it will allow me to determine where the crossover point is best placed. Given the plethora of drivers available, it could be a pig of a job to optimise/marry them to the Spendors, which will remain unmodified and that doesn't include the way the drivers perform in whatever enclosure I put them in.
So, that is a cracking suggestion, thank you.
However, your suggestion actually chimes with me, insofar as it will allow me to determine where the crossover point is best placed. Given the plethora of drivers available, it could be a pig of a job to optimise/marry them to the Spendors, which will remain unmodified and that doesn't include the way the drivers perform in whatever enclosure I put them in.
So, that is a cracking suggestion, thank you.