building Troels Gravesenjenzen Er

[kkraft67]

hey everyone, doing a jenzen er build, had a question about a possible alternative bass driver for a little lower response. i am doing the sealed cabinet version, and from what I have read looking at about 34 for the f3 on the 10" woofer, I wanted to know ya'lls opinion on using the sb acoustics SB29NRX75-6 as an alternative. any thoughts or suggetions appreciated
thanks
Kelvin

 

[system7]

Looks good:
Jenzen CA

200Hz crossover to the SEAs CA26RFX 10" bass, 6.2R DC, 29Hz Fs, Qts 0.34, Le 1.95mH:

H1305-08 CA26RFX

SB Acoustics 10" SB29NRX75-6. 4.2R DC, 21Hz Fs, Qts 0.35, Le 1.8mH: 10" SB29NRX75-6 :: SB Acoustics

Both 90dB efficiency in the area of interest. Both about $160. I can't imagine the SB is going to sound much different, but some crossover and tuning changes needed for the lower DCR SB. Why bother? BTW, not a closed box driver in either case really. But possibly will sound OK in closed box.

 

[Jay]

Why not ask Troels directly? IME, you cannot design a good speaker and then plug different driver and expect an improvement.

 

[eriksquires]

hey everyone, doing a jenzen er build, had a question about a possible alternative bass driver for a little lower response. i am doing the sealed cabinet version, and from what I have read looking at about 34 for the f3 on the 10" woofer, I wanted to know ya'lls opinion on using the sb acoustics SB29NRX75-6 as an alternative. any thoughts or suggetions appreciated
thanks
Kelvin

Hi KKraft,

Depends. If you know how to integrate drivers and crossovers, sure. Otherwise, my suggestion is to stick to the kit, make it, then learn to measure and analyze it.

I think once you add the room gain the Jenzen SEAS Er speaker will be flatter and deeper than you realize. If you really want the extension, doing the ported version is going to get you much better results than arbitrarily swapping woofers.

Also, for really deep bass you need to invest in room acoustics before bigger/deeper drivers. Everyone rolls their eyes, and goes and buys an even bigger sub-woofer when I say this, but it's true.

Best,


Erik

 

[kkraft67]

Thanks everyone, I goofed on my post, I meant to say I was building the ported version. my thinking was similar qts and le could be a direct drop in aside from the impedance of the driver. I am still learning how the components in a crossover effect overall sound of the drivers.

 

[system7]

snip... I am still learning how the components in a crossover effect overall sound of the drivers.

In other words, you don't have a clue! Not hard to adapt a filter for a lower impedance bass, as it goes. Proportionately smaller coil, bigger cap. But maybe some knock-on effects on loudness elsewhere.

Retuning the cabinet is what I wouldn't fancy. I mean, really, if it ain't broke, don't fix it!