[Harvey Clarke (UK)]

I think I my Toshiba HD-A1’s analog output, Centre Speaker Bass Management might be malfunctioning.

Here’s why:………..I have set the Speaker Distances and Crossover settings (80Hz) on the HD-A1 as close as possible to the same settings on my Lexicon MC-8 Digital Controller. (The Lexicon MC-8 in 5.1a Bypass Mode allows no control of Speaker Crossover settings, Speaker Distances and audio (tone) controls).

I have M&K THX Speakers (S-150 THX for L/C/R, MX-350 THXMkII Sub and Surround 55 MkII Tripoles for Side L/R and Rear L/R).

With the HD-A1 Speaker Sizes set to correct setting of ‘Small’, the HD-A1 test tone sounds identical on the Front Left and Right speakers and surrounds but not the Centre which has bass content coming out of it as well! It is also clearly evident when listening to a soundtrack. This is despite the Centre Speaker having exactly the same settings on the HD-A1 as the Front Left and Front Right Speakers have.

So why is the Centre speaker receiving bass content. I don’t know, having posted this as a query on SMR Audio/Video Forums I am told it must be a fault. However, the dealer in the UK who sold me the unit insists that he has had this same Centre Speaker problem with other units. I would appreciate confirmation from other analog users as to whether a problem does exist or whether I have a faulty HD-A1.

Once again my thanks in advance……………Harvey

[Royce H]

Harvey, set your center speaker to "Large" and the test tone will sound the same as from the other speakers. On my XA1, setting the center either way didn't seem-to me, at least-to affect its sound with real program material.

[MTrotter]

Hey, I noticed the same thing. When setting the center speaker to "small", the test tone has bass in it, while setting it to "large", there is no bass in the test tone. Strange.

[Harvey Clarke (UK)]

Royce – thanks for your kind reply. Now, I’ll be honest with you and tell you that this wasn’t quite the answer I was hoping for. But later in the day, in a moment of idle curiosity I tried out what you suggested and switched the HD-A1 Centre Speaker from ‘Small’ to ‘Large’ and………………..it works!………….The Bass content in the Test Tone is gone!………Pretty, Pretty, Pretty, Good.........You’re a genius as well as a Bela Lugosi fan!

But, now I want to know……..Why?

Why does the Centre Speaker when switched to ‘Large’ with all the other settings left as in my opening message do the opposite of what it’s expected to? And can we be sure that setting the Centre Speaker to ‘Large’ doesn’t affect the low frequency managment with real program material, surely when set to 'Large' it should be performing as a 'Large' Speaker rather than the 'Small' I require (and what if you do actually need it to act as a 'Large' Speaker and output low frequency, would you then have to do the upside down thing and set it to 'Small'………?)

Any answers most welcome…………

Regards - Harvey

[Royce H]

Hi, Harvey. Sorry it took so long to get back to you, but I had lots of cooking to do yesterday for our holiday and couldn't find the time to run some tests. It appears that setting the center channel to "large" makes the player's test tone come out the same as the other speakers set to "small", but it also makes the center channel sound like it's set to "large" with real program material. So, I guess the drill would be to set the center channel to "large" for doing channel balance with the player's test tones, then set it back to "small" before exiting the player's setup.

Hope this helps!