I hope the enlightened people on this forum can help. I have hooked up a Tannoy Reveal 15 studio monitor sub to my Marantz PM-75 amp. The amp has no pre out, but does have two tape outs, both with left and right channel. I have tried both tape outs, mono from left channel and sterio, both channels into the XLR sub connector. The interconnect is a reasonable quality coax, two phono/RCA into one XLR. Whatever I try I cannot drastically change the sub volume with it's own gain. The amplifier has no effect on volume as it's supplying line out only. With All Pass or Low Pass selected the sub sound is muffled/muddy just with a greater frequency range in the case of 'All Pass'. Could it be that there is a problem with the sub internal amp? The gain seems almost ineffective and at the lowest setting the volume is loud. Being a studio monitor the sound is naturally flat, but should still have good clarity regardless. Please help, I'm stuck for ideas.
To begin with, tape out is a poor choice for a subwoofer output. It has a fixed level output which means it will not automatically track volume changes. Also the output impedance of a tape out is incorrect for a subwoofer line level input.
I don't know the specific sub you own, but I would suggest trying the speaker level output from your amp running into the high level inputs on your sub. This, of course, assumes your sub has high (speaker) level inputs.
Unfortunately I have neither any other line outs on the amp or anything other than XLR line inputs. My options are an amp modification or return the sub and get a dedicated hi-fi affair, unless of course there is something wrong with the sub. Thanks
The sub will be going back and I shall bite the bullet and invest in a REL. It can be supplied with low or high level inputs. I still may have the amp modified at any rate, there may well be some improvements on my 17 year old amp that are worthwhile.