[hubert]

Hello Dave,

Once room's place selected for the speakers, and because stuffing and ports length are linked, could you give us the way, step by step, to get us the better bass and sub-bass as possible from the 1801 ?
Also, how to know the good result: do you simply trust your ears when listen to well-known CDs, or does it exist another way (I don't have possibility to measure) ?


Thanks

[David Ellis]

Stuffing a port will effectively kill the port reinforcement for the bass.  The ported cabinet will become a sealed cabinet when you stuff the port.  Because of the ported cabinets volume (about 21 liters), the W18 will become a low Q sealed woofer.

Stuffing a port will NOT enhance the bass response from the 1801.  The inverse is true.  the Sealed F3 for the sealed cabinet will be about 50 hz versus about 38hz for the ported cabinet.  However, the stuffed 1801 will roll off @ 10db instead of 24db per octave.  This might blend better with a subwoofer.

Dave

[hubert]

Hello Dave,

Thanks for your reply, but the matter isn't to stuff a port, the matter is in the relationship between trying different stuffings in the box and trying different port's lenghts.

Because this two works influence the bass response, but differently and for the stuffing  the mid-frequencys too, my question is to know the best way to make this.

In example, it is aknowledged that to place too much stuffing in the box (of course without stoping the port), kills a great part of the resonance of the air inside the box and therefore reduces bass level. But to lengthen the port reduces bass level too.
In the other way, less stuffing enhances bass level, but cuting the port shorter, too.

My question is to know the logical process to surely get good bass, without mistake.

This problem could seem evident for you and experimented diy speaker guys, but for a novice, your reply could help.
I'll make you a confidence: I'm a little experimented in stuffing diy speakers and my 1801, I know my room's characteristics and my electronics too: this last two components influence bass responce before others. But my friend Raoul, soon 1801 kit orderer is a novice; I'll help him but don't know his listening room's and electronic's characteritics, so thanks for helping us.

Best regards.

Hubert

[David Ellis]

Yep,  my mistake.  I thought you were asking another question.  I am sorry.

In example, it is aknowledged that to place too much stuffing in the box (of course without stoping the port), kills a great part of the resonance of the air inside the box and therefore reduces bass level. But to lengthen the port reduces bass level too.
In the other way, less stuffing enhances bass level, but cuting the port shorter, too.

You understand matters correctly.  Less stuffing increases box resonance.  A shorter port will raise the frequency of port bass reinforcement and provide more audible boom.

So, I suggest you start with the midrange.  Since more stuffing will kill more of the backwave, add stuffing until the midrange sounds correct (i.e. non-resonant).  After you arrive at a desirable midrange with the least stuffing possible, tune the port for the most desirable bass.

Dave

[hubert]

Ah,

Yes, your reply is exactly what I'd wish. Now, I'll able to correctly adjust Raoul's 1801.

Thanks Dave.

Hubert