I have been expermenting and searching for an ideal(??) sub combo for my Quad 2905s and believe am almost there. As rightly pointed out there are 2 ways to go : using an external crossover like a Bryston 10 Sub or a Marchand to block out all signals below 40hz or so. This has the reported advantage of letting the Quads play a lot louder without the protection circuit kicking in.
I, however, chose to go without an external crossover. Have experimented with a variety of RELs. The advantage of a REL, IMHO, is that its fed from the speaker terminals and can be tuned to kick in just below the lowest frequency of the 2905s ie 27hz. The RELs kick in around 30hz, hence there is no smearing or overlap between the subs and the main Quads.
Currently am using a REL 505(500watts) and a 305(300watts) in a room : 24x14x10. I plan to match the subs and eventually acquire a 2nd 505. I wonder if this will make a huge difference.
The results in a largely vinyl system are pretty impressive and to my surprise the Quads are playing louder today than ever before. I don't understand the explanation for this eg the numeric display on my Conrad Johnson preamp has a max reading of 99 and I can drive the Quads to 96 or 97 with vinyl as the source. This never happened before the subs arrived.
IMHO the RELs provide a sweet and tuneful bass without being over powering. The holographic midrange of the Quads gels perfectly with the RELs in the context of musical genres I value.
The Quad JL Audio route is also highly recommended but thats something I was unable to pursue.
All the best.
I, however, chose to go without an external crossover. Have experimented with a variety of RELs. The advantage of a REL, IMHO, is that its fed from the speaker terminals and can be tuned to kick in just below the lowest frequency of the 2905s ie 27hz. The RELs kick in around 30hz, hence there is no smearing or overlap between the subs and the main Quads.
Currently am using a REL 505(500watts) and a 305(300watts) in a room : 24x14x10. I plan to match the subs and eventually acquire a 2nd 505. I wonder if this will make a huge difference.
The results in a largely vinyl system are pretty impressive and to my surprise the Quads are playing louder today than ever before. I don't understand the explanation for this eg the numeric display on my Conrad Johnson preamp has a max reading of 99 and I can drive the Quads to 96 or 97 with vinyl as the source. This never happened before the subs arrived.
IMHO the RELs provide a sweet and tuneful bass without being over powering. The holographic midrange of the Quads gels perfectly with the RELs in the context of musical genres I value.
The Quad JL Audio route is also highly recommended but thats something I was unable to pursue.
All the best.